Research On The Wing Dynamics Performance Of A Bionic Flapping-wing Aircraft

Since DARAP put forward the concept of micro-flapping-wing aircraft in the United States,countries around the world have begun to pay attention to and study micro-flapping-wing aircraft.Because of its attractive application prospects in defense,military,civil and other fields,micro-flapping-wing aircraft has become a hot research topic in today's world.Based on the research of bat flight,the dynamic characteristics of bat-like wing are analyzed by using finite element theory and computational fluid dynamics.The conclusions drawn in this paper can provide some reference for the design of bionic flapping-wing micro-aircraft.In this paper,a folding and fluttering model of bat-like wing is established to imitate the wing-hand structure of bat,and the static analysis of the model is carried out.The model is optimized according to the stress and deformation nephogram.Static calculation of two different material models is carried out,and the material category is analyzed.The influence of sex on the stiffness of bionic wing.The dynamic characteristics of bat-like wing were studied,and the modal analysis of bionic wing models with different structural parameters was carried out.The effects of parameters on the structural modal characteristics were obtained and the scheme with better modal characteristics was found out.The modal analysis of two different material models was carried out,and the effects of material properties on the modal characteristics of bionic wing were found out.The transient dynamic analysis of bionic wing was carried out.The variation law of stress and deformation of bionic wing under dynamic load is obtained,and the influence of natural frequency of bionic wing structure on its vibration response is found.The aerodynamic characteristics of bat-like wing are preliminarily studied,and the three-dimensional flow around the bionic wing is analyzed at low Reynolds number.The flow field characteristics of bat-like wing hovering in the air at a certain angle of attack between the wing hand and the horizontal plane are studied,and the generating mechanism of the lift force of the bionic wing is explained.Through the theoretical analysis and calculation of the flapping-wing driving mechanism,the analytical flapping-wing motion is obtained.Based on the model,FLUENT software is used to calculate the dynamic grid,and the effects of flutter frequency,inflow velocity and inflow angle on the lift-drag coefficient of flapping wing are analyzed.Finally,the vibration modal experiment of the bat wing is carried out.The first four natural frequencies and mode shapes of the model are measured by hammering method,and the reliability of the simulation results is verified by comparing with the simulation data.